For screen lock settings see Lock screen options.
In this section:
Add or remove a PIN lock to the SIM card that is currently in the device.
Controls whether passwords typed into your Android device should be visible on the screen.
Configure which special apps are allowed to have greater-than-normal overall access to your device, to perform system maintenance or configuration.
Enable or disable the ability to install apps that come from third-party sources, other than the Google Play Store or your manufacturer's app store.
Whether to allow Google to check all apps you install against its database to check for any known viruses or harmful behavioral.
Lists the certificate authority (CA) companies that this device regards as "trusted" for the purposes of establishing secure connections such as HTTPS.
Allows the installation of a security certificate, such as a trusted Certificate Authority certificate, from a file stored on your phone's storage.
Quickly remove all user-installed trusted credentials from the device, leaving only the standard list of system-installed credentials.